I've been asked to look for notebooks for my office that have built-in
serial ports. We've already used USB-to-serial adapters and port
multipliers with mixed success; we are kind of leery of using PCMCIA
serial ports. And we'd like to use these notebooks on the go so docks
are out of the question. Can I get the big OEMs to sell me a few of
these or am I out of luck with them?

Wow, with /serial/ ports? Doh. I don't know, I would suspect the
manufacturers don't make many with serial ports any more. You might get
lucky. My USB to Serial adapter works perfectly every time. Are you
needing more than one serial port on the notebook?

My Thinkpad T600's had serial ports. My T40 does not. Wish it did, as I
am fighting with a Prolific PL2303 USB to Serial Adapter to try to talk
to a Hewlett-Packard Hp48GX calculator....never connects.

When all you have is a hammer everything looks like a nail, but
sometimes the right tool is needed to do the job!